The importance of data has increased during the last decade while the cost of data storage medium has decreased, thus motivating data storage vendors to provide data protection schemes that are based upon duplication of data.
One of these protection schemes is known as mirroring. Mirroring involves repetitively generating one or more duplicates of data. A real copying relationship can be established between one production (or primary) site and one or more remote (or secondary) sites. In a multiple remote site environment data from a single production site is mirrored on multiple remote sites.
The following patent and patent application, all being incorporated herein by reference provide various example of some state of the art data protection schemes: U.S. Pat. No. 6,957,362 of Armangau, U.S. patent application publication serial number 2005/0071708 of Bartfai et al. and U.S. patent application publication serial number 2003/0126387 of Watanabe.
An establishment of a real copying relationship between a primary site and a remote site requires that the primary site receives remote site information that may include, for example, a remote site address, a remote site identifier, a remote site communication and storage configuration and the like.
Mirroring in a multiple remote site environment as well as in a single remote site environment requires a synchronization process that can be time consuming.
A multiple remote site environment is more robust than a single remote site environment. Once the primary site fails one of the remote sites becomes (at least until the primary site is recovered) a current primary site.
In many cases the current primary site is not aware of all the remote site information, and a learning period is required for gaining the remote site information. During this learning period the current primary site can request the remote site information from the remote sites.
In various prior art solutions, once the learning period ends the current primary site performs a full-volume synchronization during which it sends its entire content to the remote sites.
There is a need to provide efficient methods, systems and computer program products for copying data.